Silicon compounds derived from ascorbic acid

ABSTRACT

The invention concerns novel silicon compounds derived from ascorbic acid consisting of a silicon-containing chain or of silanes, comprising at least a radical A of formula (I) wherein: at least one of the radicals L is a divalent radical for fixing A on the silicon chain. The invention further concerns methods for preparing said compounds, compositions, in particular cosmetic or pharmaceutical, containing them, and their use as antioxidant and/or anti-free radical agent, particularly for treating oxidant stress, for treating the effects of exposure to the sun and for preventing ageing.

This application is a 371 of PCT/FR00/02713 filed Sep. 29, 2000.

The present invention relates to novel fat-soluble and stablesilicon-containing derivatives of ascorbic acid. The invention alsorelates in particular to cosmetic and pharmaceutical compositionscomprising these novel derivatives, as well as their use.

A number of derivatives of silicon are known. Thus, patent applicationFR2645863 describes molecular complexes formed of a compound belongingto the silanol family and of an alkali metal or ammonium derivative ofan organic or inorganic acid. Molecular combinations are thus obtainedwhich have the advantage of being soluble in water. This document citesin particular the molecular complex formed of a monomethylsilanetrioland of potassium ascorbate. However, as is specified in this document,the stability of these complexes is not very good, in particular whenthey are in concentrated solution. In particular, they tend topolymerize, which causes their partial insolubilization. A2,3,5,6-bis(dimethylsilyl)ascorbate or ascorbosilyl is also known frompatent application WO96/10575; in this case, it is a precursor ofreactive silanol functions and is therefore also unstable.

The aim of the present invention is to provide novel silicon-containingcompounds derived from ascorbic acid, the said compounds beingfat-soluble and having good stability both in the dry state and indilute or concentrated solution.

The subject of the invention is therefore novel silicon-containingcompounds derived from ascorbic acid, as are defined below.

Another subject of the invention is a method of preparing the compoundsof formulae (2) to (4) defined below, by hydrosilylation of thecorresponding siloxane or silane derivative represented by one of theformulae (5) to (7) defined below, on an organic derivative of ascorbicacid chosen from the compounds of formula (I′) defined below, followedby deprotection of the compound obtained, for example by acid hydrolysisof the isopropylidenes and/or debenzylation by catalytic hydrogenation.

Another subject of the invention is a method of preparing the silanederivatives of formula (2) defined below by reacting a derivative offormula (I′″), defined below, with a silane derivative of the followingformula (8)

in which Hal represents a halogen and more particularly chlorine oriodine and the radicals R₁, R′₁, R′₂. R′₃, V, p and q have the samemeanings as above.

Yet another subject of the invention is an in particular cosmetic orpharmaceutical composition comprising a cosmetically or pharmaceuticallyacceptable medium and at least one silicon-containing compound derivedfrom ascorbic acid as defined above.

Another subject of the invention is the use of at least one suchsilicon-containing compound derived from ascorbic acid as antioxidantand/or anti-free-radical agent, in particular in a cosmetic orpharmaceutical composition.

In particular, this use may be cosmetic for, or in a cosmeticcomposition intended for, treating oxidative stress and/or treating theeffects of exposure to sunlight and/or preventing ageing in particularof the skin, the hair, the eyelashes, the eyebrows and/or the nails.

This use may also be for the preparation of a pharmaceutical compositionintended for treating oxidative stress and/or treating the effects ofexposure to ionizing or solar radiation, and/or preventing ageing inparticular of the skin, of the hair, of the eyelashes, of the eyebrowsand/or of the nails, and/or treating the effects of the use of certainmedicaments which generate free radicals.

Thus, the applicant has found that by covalently grafting one or moreascorbic acid derivatives onto a silicon-containing chain, novelcompounds were obtained which had very good properties of solubility inthe customary organic solvents, in particular in fatty substances suchas oils, as well as high stability in these media or as such.

Moreover, it was observed that these compounds had excellent cosmeticproperties.

The compounds according to the invention are therefore characterized inthat

either they consist of a silicone-containing chain comprising at leastone unit of formula (1):

or they are silanes corresponding to the following formula (2):

A—SiR′₁R′₂R′₃  (2)

in which:

R denotes a linear, cyclic or branched, saturated or unsaturated,optionally partially or completely halogenated, C₁-C₃₀ hydrocarbonradical or a trimethylsilyloxy group of formula —O—SiMe₃;

a is equal to 1 or 2,

R′₁, R′₂, R′₃, which are identical or different, are chosen from linearor branched C₁-C₈ alkyl radicals, linear or branched C₁-C₈ alkenylradicals, or a trimethylsilyloxy group;

A is a radical of the following formula (I):

in which L₁, L₂, L₃ and L₄ represent hydrogen or a divalent radical offormula (a) or (a′) allowing the attachment of the radical A onto thesilicon-containing chain, with the proviso that at least one of theradicals L₁, L₂, L₃ and L₄, preferably only one of the said radicals L₁,L₂, L₃ and L₄, represents the said divalent radical of the followingformula (a) or (a′):

in which:

V is a linear or branched, saturated or unsaturated, divalent C₁-C₆hydrocarbon radical optionally substituted with a hydroxyl radical or alinear or branched, saturated or unsaturated C₂-C₈ alkoxy radical;

R₁ represents a hydrogen atom, a hydroxyl radical or a linear orbranched, saturated or unsaturated C₁-C₈ hydrocarbon radical;

p is 0 or 1, q is 0 or 1, it being understood that p+q is different from0.

The compounds according to the invention consisting of asilicone-containing chain comprising at least one unit of formula (1)above therefore comprise in particular at least one unit of formula(1a):

and/or at least one unit of formula (1b):

Preferably, they may comprise in addition at least one other unit, forexample of the (di-)alkylsiloxane type of formula (1c):

Thus, they may in particular be represented by one of the followingformulae (3) or (4):

in which:

the radicals B, which are identical or different, are chosen from theradicals R and A,

r is an integer between 0 and 50 inclusive, preferably between 0 and 5,

s is an integer between 0 and 20 inclusive, preferably chosen from 0, 1or 2, with the proviso that if s=0, then at least one of the tworadicals B represents A,

u is an integer between 1 and 6 inclusive, preferably chosen from 1 or2,

t is an integer between 0 and 9 inclusive, preferably chosen from 2, 3or 4,

it being understood that t+u is between 3 and 10 inclusive, and ispreferably equal to 3, 4, 5 or 6.

Preferably, the radicals R, which are identical or different, are chosenfrom linear, cyclic or branched, saturated or unsaturated C₁-C₁₈hydrocarbon radicals and linear or branched, saturated or unsaturated,partially halogenated, in particular fluorinated, C₁-C₈ hydrocarbonradicals.

Still more preferably, the radicals R, which are identical or different,are chosen from linear or branched C₁-C₁₀ alkyl radicals, the phenylradical and the linear or branched fluorinated C₁-C₈ alkyl radicals.

The methyl and 3,3,3-trifluoropropyl radicals may be mentioned inparticular. More particularly, at least 80% in numerical terms of theradicals R are methyl radicals.

Preferably, the radicals R′₁, R′₂, R′₃, which are identical ordifferent, are chosen from linear or branched C₁-C₆ alkyl radicals, inparticular methyl or ethyl radicals, and the trimethylsilyloxy group.

In general, the silicon-containing derivatives corresponding to one ofthe formulae (1), (2), (3) or (4), and having at least one of thefollowing characteristics will be more particularly preferred:

R is CH₃;

B is CH₃;

R′₁, R′₂, R′₃ represent CH₃ or the trimethylsilyloxy group;

R₁ is hydrogen or CH₃;

V is —CH₂— or —CH₂—CH(OH)CH₂—;

p is 1,

r is between 0 and 5 inclusive,

s is between 1 and 2 inclusive,

t+u is between 3 and 6.

Preferably, the divalent radicals corresponding to the formulae (a) or(a′) are chosen from linear or branched, saturated or unsaturated,optionally hydroxylated, divalent C₁-C₆ hydrocarbon radicals such as themethylene (—CH₂—), ethylene (—CH₂—CH₂—), propylene (—CH₂—CH₂—CH₂—),n-butylene (—CH₂—CH₂—CH₂—CH₂—) or isobutylene (—CH₂—CH(CH₃)—CH₂—)radicals, and the radicals —CH═CH—CH₂—, —CH═C(CH₃)—CH₂—, —CH═CH—CH(CH₃)—and —CH₂—CH(OH)—CH₂—.

Among the preferred silicon-containing derivatives corresponding to theformula (1), and more particularly to the formula (3), the followingcompounds may be mentioned:

5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]-propyloxy)-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]-propyloxy)-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-3-hydroxy-4-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disiloxanyl]propyloxy]-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-4-hydroxy-3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]-disiloxanyl]propyloxy]-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-4-[3-[3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]-propyloxy]-2-hydroxy-propyloxy]-3-hydroxy-5H-furan-2-oneand

5-(1,2-dihydroxyethyl)-3-[3-[3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]-propyloxy]-2-hydroxy-propyloxy]-4-hydroxy-5H-furan-2-one.

Among the preferred silicon-containing derivatives corresponding to theformula (2), the following compounds may be mentioned:

5-(1,2-dihydroxyethyl)-3-hydroxy-4-trimethylsilanylmethoxy-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylmethoxy)-5H-furan-2-one,

5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-trimethylsilanylpropyloxy)-5H-furan-2-one,and

5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

To prepare the derivatives of formulae (1) to (4), the procedure may beconventionally carried out using a hydrosilylation reaction startingwith the corresponding siloxane or silane derivative in which forexample all the radicals A are hydrogen atoms. This siloxane or silanederivative is called “SiH-containing derivative” in the remainder of thepresent description.

The SiH groups may be present in the chain and/or at the ends of thesilicon-containing chain. These SiH-containing derivatives are productswhich are well known in the silicone industry and are generallycommercially available. They are for example described in patents U.S.Pat. No. 3,220,972, U.S. Pat. No. 3,697,473 and U.S. Pat. No. 4,340,709.

The SiH-containing derivatives allowing the preparation of the compoundsof formulae (2) to (4) may be represented by the following formulae (5)to (7):

H—SiR′₁R′₂R′₃  (5)

in which:

R′₁, R′₂, R′₃, R, r, s, t and u have the meaning given above,

B′, which are identical or different, are chosen from the radicals R anda hydrogen atom, with the proviso that if s=0, then at least one of thetwo radicals B′ represents H.

To prepare the compounds according to the invention of formulae (2) to(4) above, the procedure may be carried out in the following manner.

A reaction of hydrosilylation of the SiH-containing derivative offormula (5), (6) or (7) is carried out, preferably in the presence of acatalytically effective quantity of a platinum catalyst, on an organicderivative of ascorbic acid chosen from the compounds of the followingformula (I′):

in which L′₁, L′₂, L′₃ and L′₄ represent benzyloxy groups or correspondto one of the following two formulae (b) and (b′):

in which R₁, V and p have the same meanings as above, it being possiblefor the radicals L′₁ and L′₂ in addition to form together with theascorbic acid residue a methylenedioxy ring substituted with at leastone C₁₋₆ alkyl group or a phenyl group, in particular with a methyl,ethyl or phenyl group, or even with two alkyl or phenyl groups;

with the proviso that at least one of the radicals L′₁, L′₂, L′₃ and L′₄represents the radical (b) or (b′).

The hydrosilylation reaction can therefore be carried out according toone of the following two reactions:

These derivatives (I′) may in particular be obtained by condensation, ina conventional manner, of an alkene or alkenyl halide with a derivativeof formula (I″):

in which L″₁, L″₂, L″₃ and L″₄ represent benzyloxy groups or a hydrogenatom, with the proviso that at least one of the radicals L″₁, L″₂, L″₃and L″₄ represent hydrogen.

These derivatives of formula (I″) may be prepared according to thecustomary procedures which are well known to persons skilled in the art;some are in particular described in patent application EP411184.

After the hydrosilylation of the SiH-containing derivative of formulae(5), (6) or (7) on the ascorbic acid derivative of formula (I′), it ispossible to carry out a deprotection of the compound obtained, accordingto the conventional deprotection methods known in the literature, forexample by acid hydrolysis of the isopropylidenes and/or debenzylationby catalytic hydrogenation.

The compounds of formulae (2) to (4) above according to the inventionare then obtained.

Moreover, it is possible to prepare the silane derivatives of formula(2) according to another method of synthesis which consists in reacting:

a derivative of formula (I′″):

in which L″₁, L″₂, L″₃ and L″₄ represent benzyloxy groups or a hydrogenatom,

it being possible for the radicals L″₁, L″₂ in addition to form togetherwith the ascorbic acid residue a methylenedioxy ring substituted with atleast one C₁₋₆ alkyl group or a phenyl group, in particular with amethyl, ethyl or phenyl group, or even with two alkyl or phenyl groups;

with the proviso that at least one of the radicals L″₁, L″₂, L″₃ and L″₄represents hydrogen,

with a silane derivative of the following formula (8):

in which Hal represents a halogen and more particularly chlorine oriodine and the radicals R₁, R′₁, R′₂, R′₃, V, p and q have the samemeanings as above.

The compounds according to the invention are generally present in thecompositions of the invention in proportions of between 0.1% and 10% byweight, preferably between 0.5% and 5% by weight, relative to the totalweight of the composition.

These compositions, which may in particular be cosmetic orpharmaceutical compositions, therefore comprise moreover a cosmeticallyor pharmaceutically acceptable medium, that is to say a mediumcompatible with all keratinous materials such as the skin of the body orof the face, the mucous membranes, the semi-mucous membranes, the scalpas well as the superficial body growths such as the nails, the hair, theeyelashes and the eyebrows.

The compositions according to the invention may be provided in anycosmetically or pharmaceutically acceptable galenic form, such as in theform of a lotion, suspension, dispersion or solution in solvent oraqueous-alcoholic medium, optionally with a multiphase, optionallythickened or even gelled; in the form of a gel, a foam, a spray or anoil-in-water, water-in-oil or multiple emulsion; in the form of a loose,compact or cast powder; or in the form of a solid or an anhydrous paste.

Persons skilled in the art will be able to choose the appropriategalenic form, as well as its method of preparation, based on theirgeneral knowledge, taking into account, on the one hand, the nature ofthe constituents used, in particular their solubility in the carrier,and, on the other hand, the application envisaged for the composition.

Thus, the composition may comprise at least one ingredient chosen fromthe adjuvants normally used in the field considered, such as fattysubstances, organic solvents, water, silicones, thickeners, emollients,sunscreens, antifoams, moisturizing agents, perfumes, preservatives,surfactants, fillers, sequestrants, anionic, cationic, nonionic and/oramphoteric polymers, propellants, alkalinizing or acidifying agents,colorants, pigments or nanopigments, cosmetic active agents.

Among the fatty substances, there may be mentioned oils and/or waxes, inparticular of animal, plant, mineral or synthetic origin; C₈-C₃₂ fattyacids; C₈-C₃₂ fatty acid esters; C₈-C₃₂ fatty alcohols. There may bementioned more particularly petroleum jelly, paraffin, lanolin,hydrogenated lanolin, acetylated lanolin, hydrogenated palm oil,hydrogenated castor oil, liquid paraffin, paraffin oil, Purcellin oil,silicone oils, volatile or otherwise, isoparaffins.

Among the organic solvents, there may be mentioned C₁-C₆ lower polyolssuch as ethanol, isopropanol, propylene glycol, glycerin or sorbitol.

Of course, persons skilled in the art will be careful to choose thepossible additional compound(s) cited above and/or their quantities suchthat the advantageous properties intrinsically attached to the compoundin accordance with the invention are not, or not substantially, impairedby the addition(s) envisaged.

It has been observed that the compounds of the invention have anexcellent fat-solubility, in particular in fatty substances such asMiglyol, alcohols (in particular ethanol), glycols (in particularpropylene glycol) and silicone oils (in particular PDMS). Moreover, theybecome uniformly distributed in conventional cosmetic carrierscontaining at least one fatty phase or a cosmetically acceptable organicsolvent.

Moreover, it has been observed that the compounds according to theinvention could exhibit good antioxidant and/or anti-free-radicalproperties.

They therefore find a very special application in cosmetic orpharmaceutical compositions intended for treating oxidative stressand/or treating the effects of exposure to sunlight and/or preventingageing in particular of the skin, of the hair, of the eyelashes, of theeyebrows and/or of the nails.

The compositions comprising them therefore find a very specialapplication as a composition to be applied to the skin of the bodyand/or of the face, and/or to the hair, eyelashes, eyebrows and/ornails.

In particular, these compositions may be present to be used:

as a composition for protecting the human epidermis or the hair againstUV radiation (antisun compositions);

as a cosmetic composition for the protection or treatment or care of thehair, in particular in the form of a shampoo, lotion, gel or rinse-offcomposition, to be applied before or after shampooing, before or afterdyeing or bleaching, before, during or after permanent-waving or hairstraightening, of a hair-styling or treatment lotion or gel, of ablow-drying or hair-setting lotion or gel, of a hair lacquer, of acomposition for permanent-waving or hair straightening, for dyeing orbleaching the hair;

as a care composition for the skin of the body and/or of the face, suchas a treatment cream for the epidermis, day cream, night cream,antiwrinkle cream, moisturizing cream, cream for the hands or the feet;

as a makeup composition for the eyelashes, the eyebrows, the hair, thebody or the face, such as foundation, lipstick, eyeshadow, blusher,eyeliner, mascara, dyeing gel, nail varnish.

The invention is illustrated in greater detail in the followingexamples.

EXAMPLE 1 Preparation of5-(1,2-dihydroxyethyl)-3-hydroxy-4-trimethylsilanylmethoxy-5H-furan-2-one

a) 1st step: preparation of5-(2,2-dimethyl-[1,3]-dioxolan-4-yl)-3-hydroxy-4-trimethylsilanylmethoxy-5H-furan-2-one

19.26 g (0.09 mol) of (iodomethyl)trimethylsilane are added, undernitrogen, to a mixture of 12.96 g (0.06 mol) of5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3,4-dihydroxy-5H-furan-2-one(prepared according to M. E. Jung et al. J. Am. Chem. Soc., 1980, 102,6304) and 7.56 g (0.09 mol) of sodium bicarbonate in 75 ml of dimethylsulphoxide (DMSO).

The whole is heated at 55° C. for 19 hours. The mixture is cooled andpoured into 150 ml of water. The mixture is stirred for 1 hour at roomtemperature (25° C.). The precipitate is filtered. It is rinsed withwater and dried under vacuum.

11.1 g (yield 61%) of the desired product are obtained in the form of awhite solid.

¹H NMR spectrum (CDCl₃, 200 MHz): 4.40 (d, J=4 Hz, 1H); 4.15 (m, 2H);4.07 (m, 1H); 3.89 (m, 2H); 1.28 (s, 3H); 1.25 (s, 3H); 0.00 (s, 9H).

b) 2nd step: preparation of5-(1,2-dihydroxyethyl)-3-hydroxy-4-trimethylsilanylmethoxy-5H-furan-2-one

The preceding derivative (6.4 g, 0.021 mol) in a mixture of 80 ml ofmethanol and 40 ml of 2 N aqueous HCl is heated for 2 hours at 50° C.The mixture is evaporated under vacuum at 40° C. in order to remove mostof the methanol. The residue is poured into 200 ml of water. The mixtureis neutralized with sodium bicarbonate. The mixture is extracted withethyl acetate. The organic phase is washed with salt water and it isdried over Na₂SO₄. The solvent is evaporated.

A colourless oil is obtained which is purified on silica (eluant:cyclohexane/ethyl acetate 50/50). 4.0 g (yield 72%) of the desiredproduct are obtained in the form of a colourless oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 4.54 (d, J=2 Hz, 1H); 4.22 (m, 2H);3.80 (m, 3H); 0.01 (s, 9H).

EXAMPLE 2 Preparation of5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylmethoxy)-5H-furan-2-one

a) 1st step: preparation of4-benzyloxy-5-(2,2-dimethyl-[1,3]-dioxolan-4-yl)-3-hydroxy-5H-furan-2-one

Benzyl bromide (13.0 ml, 0.11 mol) is added to a mixture of5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3,4-dihydroxy-5H-furan-2-one (21.62g, 0.1 mol) and sodium bicarbonate (12.6 g, 0.15 mol) in 125 ml of DMSO,under nitrogen. The mixture is heated at 55° C. for 16 hours. It iscooled and it is poured into 250 ml of water. The mixture is extractedwith ethyl acetate. The organic phase is washed with salt water anddried over Na₂SO₄. The solvent is evaporated.

A brown oil is obtained which is purified on silica (eluant:cyclohexane/ethyl acetate 75/25) to give 13.8 g (yield 45%) of thedesired product in the form of a slightly yellow oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 7.56 (m, 5H); 5.77 (s, 2H); 4.77 (d,J=4 Hz, 1H) 4.46 (m, 1H); 4.20 (m, 2H); 1.55 (s, 3H); 1.48 (s, 3H).

b) 2nd step: preparation of4-benzyloxy-5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3-trimethylsilanylmethoxy-5H-furan-2-one

(Iodomethyl)trimethylsilane (6.15 g, 0.029 mol) is added to a mixture ofthe preceding product (8.0 g, 0.026 mol) and potassium carbonate (4.32g, 0.031 mol) under nitrogen. The mixture is stirred at room temperaturefor 48 hours. It is poured into 200 ml of water. The mixture isextracted with ethyl acetate. The organic phase is washed with saltwater and dried over Na₂SO₄.

After evaporation of the solvent, an orange-coloured oil (10.5 g) isobtained which is used directly in the next step.

¹H NMR spectrum (CDCl₃, 200 MHz): 7.27 (m, 5H); 5.34 (s, 2H); 4.40 (d,J=3 Hz, 1H); 4.15 (m, 1H); 3.99 (m, 2H); 3.77 (m, 2H); 1.28 (s, 3H);1.24 (s, 3H); 0.00 (s, 9H).

c) 3rd step: preparation of4-benzyloxy-5-(1,2-dihydroxyethyl)-3-trimethylsilanylmethoxy-5H-furan-2-one

The preceding product (10.5 g, 0.026 mol) is dissolved in 100 ml ofmethanol. 50 ml of a 2 N aqueous HCl solution are added. The mixture isheated at 50° C. for 2 hours. The mixture is evaporated under vacuum at40° C. in order to remove the methanol. The residue is poured into 200ml of water. The mixture is neutralized with sodium bicarbonate. Themixture is extracted with ethyl acetate. The organic phase is washedwith salt water and dried over Na₂SO₄. The solvent is evaporated to givea yellow oil which is purified on silica (eluant: cyclohexane/ethylacetate 60/40).

5.6 g (yield 61% in two steps) of the desired product are obtained inthe form of a yellowish oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 7.27 (m, 5H); 5.35 (s, 2H); 4.55 (d,J=3 Hz, 1H); 3.74 (m, 5H); 2.31 (broad d, 1H); 2.06 (t, broad, 1H); 0.00(s, 9H).

d) 4th step: preparation of5-(1,2-dihydroxyethyl)-4-hydroxy-3-trimethylsilanylmethoxy-5H-furan-2-one

The preceding derivative (5.2 g, 0.015 mol) is dissolved in 100 ml ofethyl acetate. 100 ml of absolute ethanol are added. 1 g of 5% palladiumon carbon is then added. The mixture is stirred under 12 bar of hydrogenfor 7 hours at room temperature. The catalyst is filtered.

The solvent is evaporated to give 3.8 g (yield 98%) of the desiredproduct in the form of a white solid.

¹H NMR spectrum (acetone-d₆, 200 MHz): 4.74 (d, J=2 Hz, 1H); 3.82 (m,1H); 3.71 (m, 2H); 3.63 (m, 2H); 0.00 (s, 9H).

EXAMPLE 3 Preparation of5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

a) 1st step: preparation of5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3-hydroxy-4-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

3-iodopropyltrimethylsilane (14.5 g, 0.06 mol) is added to a mixture of5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-3,4-dihydroxy-5H-furan-2-one (8.64g, 0.04 mol) and sodium bicarbonate (5.04 g, 0.06 mol) in 50 ml ofdimethyl sulphoxide under nitrogen. The mixture is heated at 55° C. for24 hours. It is cooled and it is poured into 300 ml of water. Themixture is extracted with ethyl acetate. The organic phase is washedwith salt water and it is dried over Na₂SO₄. The solvent is evaporated.

A brown oil is obtained which is purified on silica (eluant:cyclohexane/ethyl acetate 75/25) to give 8.8 g (yield 67%) of thedesired product in the form of a slightly yellow oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 4.53 (d, J=4 Hz, 1H); 4.40 (t, J=7 Hz,2H); 4.25 (m, 1H); 3.98 (m, 2H); 0.52 (m, 2H); 0.00 (s, 9H).

b) 2nd step: preparation of5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

The preceding product (8.89 g, 0.03 mol) is dissolved in 100 ml ofmethanol. 50 ml of a 2 N aqueous HCl solution are added. The mixture isheated at 50° C. for 2 hours. The mixture is evaporated under vacuum at40° C. in order to remove the methanol. The residue is poured into 100ml of water. The mixture is neutralized with sodium bicarbonate. Themixture is extracted with ethyl acetate. The organic phase is washedwith salt water and dried over Na₂SO₄. The solvent is evaporated. Theyellowish oil obtained is purified on silica (eluant: cyclohexane/ethylacetate 50/50).

5.4 g (yield 62%) of the desired product are obtained in the form of acolourless oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 4.65 (d, J=2 Hz, 1H); 4.33 (m, 2H);3.98 (m, 2H); 3.81 (m, 2H); 1.63 (m, 2H); 0.51 (m, 2H); 0.00 (s, 9H).

EXAMPLE 4 Preparation of5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

a) 1st step: preparation of4-benzyloxy-5-(2,2-dimethyl[1,3]dioxolan-4-yl)-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

3-iodopropyltrimethylsilane (12.86 g, 0.053 mol) is added to a mixtureof4-benzyloxy-5-(2,2-dimethyl[1,3]dioxolan-4-yl)-3-hydroxy-5H-furan-2-one(14.8 g, 0.048 mol) and potassium carbonate (8.0 g, 0.058 mol), undernitrogen, in 100 ml of dimethyl sulphoxide. The mixture is stirred atroom temperature for 22 hours. It is poured into 300 ml of water. Themixture is extracted with ethyl acetate. The organic phase is washedwith salt water and dried over Na₂SO₄.

After evaporation of the solvent, an orange-coloured oil is obtainedwhich is purified on silica (eluant: cyclohexane/ethyl acetate 5/1) togive 10.5 g (yield 52%) of the desired product in the form of acolourless oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 7.39 (m, 5H); 5.50 (s, 2H); 4.55 (d,J=3 Hz, 1H); 4.30 (m, 1H); 4.01 (m, 4H); 1.67 (m, 2H); 1.40 (s, 3H);1.37 (s, 3H), 0.50 (m, 2H); 0.00 (s, 9H).

b) 2nd step: preparation of4-benzyloxy-5-(1,2-dihydroxyethyl)-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

The preceding product (9.4 g, 0.025 mol) is dissolved in 80 ml ofmethanol. 40 ml of a 2 N aqueous HCl solution are added. The mixture isheated at 50° C. for 2 hours. The mixture is evaporated under vacuum at40° C. in order to remove the methanol. The residue is poured into 200ml of water. The mixture is neutralized with sodium bicarbonate. Themixture is extracted with ethyl acetate. The organic phase is washedwith salt water and it is dried over Na₂SO₄. The solvent is evaporatedto give a yellow oil which is purified on silica (eluant:cyclohexane/ethyl acetate 2/1).

8.0 g (yield 94%) of the desired product are obtained in the form of ayellowish oil.

¹H NMR spectrum (CDCl₃, 200 MHz): 7.39 (m, 5H); 5.50 (s, 2H), 4.71 (d,J=3 Hz, 1H); 4.01 (m, 3H); 3.80 (m, 2H); 2.47 (broad d, 1H); 2.21 (broadt, 1H); 0.50 (m, 2H); 0.00 (s, 9H).

c) 3rd step: preparation of5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one

The preceding derivative (7.6 g, 0.02 mol) is dissolved in 100 ml ofethyl acetate. 100 ml of absolute ethanol are added. 1.2 g of 5%palladium on carbon are then added. The mixture is stirred under 12 barof hydrogen for 7 hours at room temperature. The catalyst is filtered.

The solvent is evaporated and 5.7 g (yield 98%) of the desired productare obtained in the form of a white solid.

¹H NMR spectrum (acetone-d₆, 200 MHz): 4.84 (d, J=2 Hz, 1H); 3.96 (m,3H), 3.89 (m, 2H); 1.65 (m, 2H); 0.54 (m, 2H); 0.00 (s, 9H).

EXAMPLE 5 Antisun Cream

An antisun oil-in-water emulsion is prepared comprising:

compound of Example 1 1 g UV screen (Mexoryl ® XL) 4 g mixture ofcetylstearyl alcohol and oxyethylenated 7 g cetylstearyl alcohol (33 EO)80/20 (DEHSCONET 390 from TENSIA) mixture of glyceryl mono- anddistearate (CERASYNTH 2 g SD from ISP) polydimethylsiloxane 1.5 g (DC200Fluid from DOW CORNING) benzoate of C₁₂-C₁₅ alcohols 16 g (FINSOLV TNfrom FINETEX) glycerin 20 g demineralized water qs 100 g

EXAMPLE 6 After-shampoo Conditioning Gel for Protecting the Hair

An after-shampoo conditioning gel for protecting the hair is preparedcomprising:

compound of Example 4 2 g polydimethylsiloxane α,Ω-dihydroxylated/volatile 20 g silicone (Q2-1401 from DOW CORNING)acrylamide/2-acrylamido-2-methylpropanesulphonic acid 1 g AM crosslinkedcopolymer (SEPIGEL 305 by SEPPIC) water qs 100 g

What is claimed is:
 1. A silicon-containing compound derived fromascorbic acid and having at least one group chosen from: a)silicone-containing chains having at least one group of formula (1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is chosen froma trimethylsilyloxy group of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; a is equal to 1 or 2, R′₁, R′₂, and R′₃, whichare identical or different, are each chosen from linear and branched(C₁-C₈) alkyl groups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are each chosenfrom linear and branched, saturated and unsaturated, divalent (C₁-C₆)alkyl groups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxyl groups;groups R₁, which are identical or different, are each chosen fromhydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and p is 0 or 1; q is 0 or 1, with theproviso that that p+q is different from 0; wherein said divalent groupsof formula (a) and divalent groups of formula (a′) allow the attachmentof the radical A onto the silicon-containing chains; and provided thatat least one of L₁, L₂, L₃, and L₄ is chosen from said divalent groupsof formula (a) and divalent groups of formula (a′).
 2. A compoundaccording to claim 1, wherein only one of L₁, L₂, L₃, and L₄ is chosenfrom said divalent groups of formula (a) and divalent groups of formula(a′).
 3. A compound according to claim 1, wherein saidsilicone-containing chains comprise at least one unit chosen from: a)units of formula (1a):

b) units of formula (1b):

wherein: the groups R, which are identical or different, are each chosenfrom trimethylsilyloxy groups of formula —O—SiMe₃, and linear, cyclicand branched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, whereinthe (C₁-C₃₀) alkyl groups are optionally partially halogenated oroptionally completely halogenated; and the groups A, which are identicalor different, are each chosen from groups of formula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: the groups V, which are identical or different, are eachchosen from linear and branched, saturated and unsaturated, divalent(C₁-C₆) alkyl groups, wherein said divalent (C₁-C₆) alkyl groups areoptionally substituted with at least one group chosen from linear andbranched, saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxylgroups; the groups R₁, which are identical or different, are each chosenfrom hydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and p is 0 or 1; q is 0 or 1, with theproviso that p+q is different from 0; wherein said divalent groups offormula (a) and divalent groups of formula (a′) allow the attachment ofthe radical A onto the silicon-containing chain; and provided that atleast one of L₁, L₂, L₃, and L₄ is chosen from said divalent groups offormula (a) and divalent groups of formula (a′).
 4. A compound accordingto claim 3, wherein said silicone-containing chains further comprise atleast one unit chosen from (di-) alkylsiloxane units of formula (1c):

wherein: groups R, which are identical or different, are each chosenfrom trimethylsilyloxy groups of formula —O—SiMe₃ and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated.
 5. A compound according to claim 4, wherein saidcompound is chosen from compounds of formula (3) and compounds offormula (4):

wherein: the groups R, which are identical or different, are each chosenfrom trimethylsilyloxy groups of formula —O—SiMe₃, and linear, cyclicand branched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, whereinthe (C₁-C₃₀) alkyl groups are optionally partially halogenated oroptionally completely halogenated; and A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are chosen fromlinear and branched, saturated and unsaturated, divalent (C₁-C₆) alkylgroups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and a hydroxyl group;groups R₁, which are identical or different, are chosen from hydrogen, ahydroxyl group, and linear and branched, saturated and unsaturated(C₁-C₈) alkyl groups; and p is 0 or 1; q is 0 or 1, with the provisothat p+q is different from 0; wherein said divalent groups of formula(a) and divalent groups of formula (a′) allow the attachment of theradical A onto the silicon-containing chain; and provided that at leastone of L₁, L₂, L₃, and L₄ is chosen from said divalent groups of formula(a) and divalent groups of formula (a′); groups B, which are identicalor different, are chosen from R and A as defined above; r ranges from 0to 50; s ranges from 0 to 20, provided that if s=0, then at least one ofthe groups B represents A; u ranges from 0 to 6; t ranges from 0 to 9;with the proviso that t+u ranges from 3 to
 10. 6. A compound accordingto claim 5, wherein r ranges from 0 to
 5. 7. A compound according toclaim 5, wherein s ranges from 0 to
 2. 8. A compound according to claim5, wherein u is chosen from 1 and
 2. 9. A compound according to claim 5,wherein t ranges from 2 to
 4. 10. A compound according to claim 5,wherein t+u is chosen from 3, 4, 5, and
 6. 11. A compound according toclaim 1, wherein the group R is chosen from linear, cyclic, andbranched, saturated and unsaturated (C₁-C₁₈) alkyl groups and partiallyhalogenated, linear and branched, saturated and unsaturated (C₁-C₈)alkyl group groups.
 12. A compound according to claim 11, wherein thegroup R is chosen from partially fluorinated, linear and branched,saturated and unsaturated (C₁-C₈) alkyl groups.
 13. A compound accordingto claim 11, wherein the group R is chosen from linear and branched(C₁-C₁₀) alkyl groups, phenyl groups, and linear and branched,fluorinated (C₁-C₈) alkyl groups.
 14. A compound according to claim 11,wherein the group R is chosen from a methyl group and a3,3,3-trifluoropropyl group.
 15. A compound according to claim 5,wherein at least 80% of the groups R are methyl groups.
 16. A compoundaccording to claim 1, wherein R′₁, R′₂, R′₃, which are identical ordifferent, are chosen from linear and branched (C₁-C₆) alkyl groups andtrimethylsilyloxy groups.
 17. A compound according to claim 16, whereinR′₁, R′₂, R′₃ are chosen from methyl groups and ethyl groups.
 18. Asilicon-containing compound derived from ascorbic acid having at leastone group chosen from: a) silicone-containing chains having at least onegroup of formula (1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is a methylgroup; a is equal to 1 or 2, R′₁, R′₂, and R′₃, which are identical ordifferent, are each chosen from methyl groups and trimethylsilyloxygroups of formula —O—SiMe₃; A is chosen from groups of formula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V which are identical or different, are each chosenfrom —CH₂— groups and —CH₂—CH(OH)CH₂— groups; groups R₁, which areidentical or different, are each chosen from hydrogen and methyl groups;and p is 0 or 1; q is 0 or 1, with the proviso that p+q is differentfrom 0; wherein said divalent groups of formula (a) and divalent groupsof formula (a′) allow the attachment of the group A onto thesilicon-containing chains; and provided that at least one of L₁, L₂, L₃,and L₄ is chosen from said divalent groups of formula (a) and divalentgroups of formula (a′).
 19. A compound chosen from compounds of formula(3) and compounds of formula (4):

wherein: groups R are methyl groups; groups A, which are identical ordifferent, are chosen from groups of formula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are each chosenfrom —CH₂— groups and —CH₂—CH(OH)CH₂— groups; groups R₁, which areidentical or different, are each chosen from hydrogen and methyl groups;and p is 0 or 1; q is 0 or 1, with the proviso that p+q is differentfrom 0; wherein said divalent groups of formula (a) and divalent groupsof formula (a′) allow the attachment of the radical A onto thesilicon-containing chain; and provided that at least one of L₁, L₂, L₃,and L₄ is chosen from said divalent groups of formula (a) and divalentgroups of formula (a′); groups B are methyl groups; r ranges from 0 to5; s ranges from 1 to 2; u ranges from 1 to 6; t ranges from 0 to 5;with the proviso that t+u ranges from 3 to
 6. 20. A compound accordingto claim 1, wherein said divalent groups of formula (a) and saiddivalent groups of formula (a′) are chosen from optionally hydroxylated,linear and branched, saturated and unsaturated, divalent (C₁-C₆) alkylgroups.
 21. A compound according to claim 20, wherein said divalentgroups of formula (a) and said divalent groups of formula (a′) arechosen from methylene (—CH₂—) groups, ethylene (—CH₂—CH₂—) groups,propylene (—CH₂—CH₂—CH₂—) groups, n-butylene (—CH₂—CH₂—CH₂—CH₂—) groups,isobutylene (—CH₂—CH(CH₃)—CH₂—) groups, —CH═CH—CH₂— groups,—CH═C(CH₃)—CH₂— groups, —CH═CH—CH(CH₃)— groups, and CH₂—CH(OH)—CH₂—groups.
 22. A compound according to claim 1, wherein said compound ischosen from:5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy)-5H-furan-2-one;5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy)-5H-furan-2-one;5-(1,2-dihydroxyethyl)-3-hydroxy-4-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy]-5H-furan-2-one;5-(1,2-dihydroxyethyl)-4-hydroxy-3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy]-5H-furan-2-one;5-(1,2-dihydroxyethyl)-4-[3-[3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy]-2-hydroxy-propyloxy]-3-hydroxy-5H-furan-2-one;5-(1,2-dihydroxyethyl)-3-[3-[3-[2-methyl-3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propyloxy]-2-hydroxy-propyloxy]4-hydroxy-5H-furan-2-one;5-(1,2-dihydroxyethyl)-3-hydroxy-4-trimethylsilanylmethoxy-5H-furan-2-one;5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylmethoxy)-5H-furan-2-one;5-(1,2-dihydroxyethyl)-3-hydroxy-4-(3-trimethylsilanylpropyloxy)-5H-furan-2-one;and5-(1,2-dihydroxyethyl)-4-hydroxy-3-(3-trimethylsilanylpropyloxy)-5H-furan-2-one.23. A method for preparing the compound of claim 19 comprising: A)grafting a corresponding Si—H containing derivative onto an organicderivative of ascorbic acid via hydrosilylation to form a product;wherein: 1) the corresponding Si—H containing derivative is chosen fromcompounds of formula (5), formula (6) and formula (7):H—SiR′₁R′₂R′₃  (5)

 wherein: groups R, which are identical or different, are chosen fromtrimethylsilyloxy groups of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; R′₁, R′₂, and R′₃, which are identical ordifferent, are each chosen from linear and branched (C₁-C₈) alkylgroups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; r ranges from 0 to 50; sranges 0 from 20; u ranges from 1 to 6; t ranges from 0 to 9; with theproviso that t+u ranges from 3 to 10; groups B′, which are identical ordifferent, are chosen from groups R and hydrogen atoms, provided that ifs=0, then at least one of the two groups B′ is a hydrogen group; and 2)the organic derivative of ascorbic acid is chosen from the compounds offormula (I′):

 wherein: L′₁, L′₂, L′₃, and L′₄, are chosen from benzyloxy groups,groups of formula (b), and groups of formula (b′):

 wherein: the groups V, which are identical or different, are eachchosen from linear and branched, saturated and unsaturated, divalent(C₁-C₆) alkyl groups, wherein said divalent (C₁-C₆) alkyl groups areoptionally substituted with at least one group chosen from linear andbranched, saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxylgroups; the groups R₁, which are identical or different, are each chosenfrom hydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and p is 0 or 1; and further whereinL′₁ and L′₂ may optionally form, together with the organic derivative ofascorbic acid, a methylenedioxy ring substituted with at least one groupchosen from (C₁-C₆) alkyl groups and phenyl groups; provided that atleast one of L′₁, L′₂, L′₃, and L′₄ is chosen from the groups of formula(b) and the groups of formula (b′); and B) subsequently deprotecting theproduct.
 24. A method for preparing the compound of claim 19, whereinthe methylenedioxy ring is substituted with at least one group chosenfrom methyl groups, ethyl groups, and phenyl groups.
 25. A method forpreparing the compound of claim 19, wherein the product is deprotectedby a process chosen from acid hydrolysis of the isopropylidenes, anddebenzylation by catalytic hydrogenation.
 26. A method for preparing thecompound of claim 19, wherein the hydrosilylation is carried out in thepresence of an effective amount of a platinum catalyst.
 27. A method forpreparing the silanes of formula (2) according to claim 1, comprising:A) grafting a corresponding Si—H containing derivative onto an organicderivative of ascorbic acid via hydrosilylation to form a product:wherein: 1) the corresponding Si—H containing derivative is chosen fromcompounds of formula (5), formula (6) and formula (7):H—SiR′₁R′₂R′₃  (5)

 wherein: groups R, which are identical or different, are chosen fromtrimethylsilyloxy groups of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; R′₁, R′₂, and R′₃, which are identical ordifferent, are each chosen from linear and branched (C₁-C₈) alkylgroups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; r ranges from 0 to 50; sranges from 0 to 20; u ranges from 1 to 6; t ranges from 0 to 9; withthe proviso that t+u ranges from 3 to 10; groups B′, which are identicalor different, are chosen from the radicals R and hydrogen, provided thatif s=0, then at least one of the two radicals B′ is hydrogen; and 2) theorganic derivative of ascorbic acid is chosen from the compounds of theformula (I′):

 wherein: L′₁, L′₂, L′₃, and L′₄ are chosen from benzyloxy groups,groups of formula (b), and groups of formula (b′):

 wherein: groups V, which are identical or different, are each chosenfrom —CH₂— groups and —CH₂—CH(OH)CH₂— groups; R₁ is chosen from hydrogenand methyl groups; and p is 1; and further wherein L′₁ and L′₂ mayoptionally form, together with the organic derivative of ascorbic acid,a methylenedioxy ring substituted with at least one group chosen from(C₁-C₆) alkyl groups and phenyl groups; provided that at least one ofL′₁, L′₂, L′₃, and L′₄ is chosen from the groups of formula (b) and thegroups of formula (b′); and B) subsequently deprotecting the product.28. A method for preparing the silanes of formula (2) according to claim27, wherein the methylenedioxy ring is substituted with at least onegroup chosen from methyl groups, ethyl groups, and phenyl groups.
 29. Amethod for preparing the silanes of formula (2), wherein the product isdeprotected by a process chosen from acid hydrolysis of theisopropylidenes, and debenzylation by catalytic hydrogenation.
 30. Amethod for preparing the silanes of formula (2), wherein thehydrosilylation is carried out in the presence of an effective amount ofa platinum catalyst.
 31. A method for preparing the silanes of formula(2) according to claim 1, comprising: reacting a derivative of formula(I′″), defined below, with a silane derivative of formula (8), definedbelow, to form a product; wherein: a) the derivative of formula (I′″)is:

 wherein: L″₁, L″₂, L″₃, and L″₄ , which are identical or different, areeach chosen from benzyloxy groups and hydrogen; further wherein L″₁ andL″₂ may optionally form, together with the organic derivative ofascorbic acid, a methylenedioxy ring substituted with at least one groupchosen from (C₁-C₆) alkyl groups and phenyl groups; provided that atleast one of L″₁, L″₂, L″₃, and L″₄ is hydrogen; and b) the silanederivative of formula (8) is:

 wherein: Hal is a halogen atom; R₁, is chosen from hydrogen, a hydroxylgroup, and linear and branched, saturated and unsaturated (C₁-C₈) alkylgroups; R′₁, R′₂, and R′₃, which are identical or different, are eachchosen from linear and branched (C₁-C₈) alkyl groups, linear andbranched (C₁-C₈) alkenyl groups, and trimethylsilyloxy groups of formula—O—SiMe₃; V is chosen from linear and branched, saturated andunsaturated, divalent (C₁-C₆) alkyl groups, wherein said divalent(C₁-C₆) alkyl groups are optionally substituted with at least one groupchosen from linear and branched, saturated and unsaturated, (C₂-C₈)alkoxy groups and a hydroxyl group; and p is 0 or 1, q is 0 or 1, withthe proviso that p+q is different from
 0. 32. A method for preparing thesilanes of formula (2), wherein Hal is chosen from chlorine and iodine.33. A composition comprising a cosmetically or pharmaceuticallyacceptable medium and at least one silicon-containing compound derivedfrom ascorbic acid having at least one group chosen from: a)silicone-containing chains having at least one group of formula (1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is chosen froma trimethylsilyloxy group of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; a is equal to 1 or 2, R′₁, R′₂, and R′₃, whichare identical or different, are each chosen from linear and branched(C₁-C₈) alkyl groups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V are identical or different, are each chosen fromlinear and branched, saturated and unsaturated, divalent (C₁-C₆) alkylgroups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxyl groups;groups R₁, which are identical or different, are each chosen fromhydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and units p, which are identical ordifferent, are each chosen from 0 and 1; q is 0 or 1, with the provisothat p+q is different from 0; wherein said divalent groups of formula(a) and divalent groups of formula (a′) allow the attachment of theradical A onto the silicon-containing chains; and provided that at leastone of L₁, L₂, L₃, and L₄ is chosen from said divalent groups of formula(a) and divalent groups of formula (a′).
 34. A composition according toclaim 33, wherein said composition is a cosmetic composition.
 35. Acomposition according to claim 33, wherein said composition is apharmaceutical composition.
 36. A composition according to claim 33,wherein said at least one silicone-containing compound is present in anamount ranging from about 0.1% to about 10% by weight, relative to thetotal weight of the composition.
 37. A composition according to claim36, wherein said at least one silicone-containing compound is present inan amount ranging from about 0.5% to about 5% by weight, relative to thetotal weight of the composition.
 38. A composition according to claim33, wherein said composition is suitable for application to a keratinousmaterial.
 39. A composition according to claim 38, wherein saidkeratinous material is chosen from body skin, facial skin, hair,eyelashes, eyebrows, mucous membranes, semi-mucous membranes, scalp, andnails.
 40. A composition according to claim 33, wherein said compositionis in any cosmetically or pharmaceutically acceptable form.
 41. Acomposition according to claim 33, further comprising at least oneadjuvant chosen from fatty substances, organic solvents, water,silicones, thickeners, emollients, sunscreens, antifoams, moisturizingagents, perfumes, preservatives, surfactants, fillers, sequestrants,anionic polymers, cationic polymers, nonionic polymers, amphotericpolymers, propellants, alkalinizing agents, acidifying agents,colorants, pigments, nanopigments, and cosmetic active agents.
 42. Acomposition according to claim 41, wherein the fatty substances arechosen from oils, waxes, (C₈-C₃₂) fatty acids, (C₈-C₃₂) fatty acidesters, and (C₈-C₃₂) fatty alcohols.
 43. A composition according toclaim 42, wherein the fatty substances are chosen from petroleum jelly,paraffin, lanolin, hydrogenated lanolin, acetylated lanolin,hydrogenated palm oil, hydrogenated castor oil, liquid paraffin,paraffin oil, Purcellin oil, volatile silicone oils, non-volatilesilicone oils, and isoparaffins.
 44. A composition according to claim41, wherein the organic solvents are chosen from (C₁-C₆) lower polyols.45. A composition according to claim 41, wherein the organic solventsare chosen from ethanol, isopropanol, propylene glycol, glycerin andsorbitol.
 46. A composition according to claim 40, wherein thecosmetically or pharmaceutically acceptable form of the composition is aform suitable for at least one of: protection of human hair against UVradiation (anti-sun compositions); protection of human epidermis againstUV radiation (anti-sun compositions); protection, treatment, and care ofhair; body skin care; face care; and makeup for a body part chosen fromeyelashes, eyebrows, hair, skin, and face.
 47. A composition accordingto claim 40, wherein the cosmetically or pharmaceutically acceptableform of the composition is chosen from shampoos, lotions, gels,rinse-off compositions, foundations, lipsticks, eyeshadows, blushers,eyeliners, mascaras, dyeing gels, nail varnishes, and creams.
 48. Acomposition according to claim 47, wherein the creams are chosen fromepidermis creams, day creams, night creams, anti-wrinkle creams,moisturizing creams, foot creams and hand creams.
 49. A method fortreating oxidative stress and/or treating the effects of exposure tosunlight and/or preventing the ageing of a keratinous materialcomprising: applying to a keratinous material an effective amount of atleast one silicon-containing compound derived from ascorbic acid havingat least one group chosen from: a) silicone-containing chains having atleast one group of formula (1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is chosen froma trimethylsilyloxy group of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; a is equal to 1 or 2, R′₁, R′₂, and R′₃, whichare identical or different, are each chosen from linear and branched(C₁-C₈) alkyl groups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are each chosenfrom linear and branched, saturated and unsaturated, divalent (C₁-C₆)alkyl groups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxyl groups;groups R₁, which are identical or different, are each chosen fromhydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and units p, which are identical ordifferent, are each chosen from 0 and 1; q is 0 or 1, with the provisothat p+q is different from 0; wherein said divalent groups of formula(a) and divalent groups of formula (a′) allow the attachment of theradical A onto the silicon-containing chains; and provided that at leastone of L₁, L₂, L₃, and L₄ is chosen from said divalent groups of formula(a) and divalent groups of formula (a′).
 50. A method according to claim49, wherein the keratinous material is chosen from skin, hair,eyelashes, eyebrows, and nails.
 51. A method for treating oxidativestress and/or treating the effects of exposure to sunlight and/orpreventing the ageing of a keratinous material comprising: applying tokeratinous material, an effective amount of a composition, comprising acosmetically or pharmaceutically acceptable medium and at least onesilicon-containing compound derived from ascorbic acid having at leastone group chosen from: a) silicone-containing chains having at least onegroup of formula (1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is chosen froma trimethylsilyloxy group of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; a is equal to 1 or 2, R′₁, R′₂, and R′₃, whichare identical or different, are each chosen from linear and branched(C₁-C₈) alkyl groups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are each chosenfrom linear and branched, saturated and unsaturated, divalent (C₁-C₆)alkyl groups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxyl groups;groups R₁, which are identical or different, are each chosen fromhydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and p is 0 or 1; q is 0 or 1, with theproviso that p+q is different from 0; wherein said divalent groups offormula (a) and divalent groups of formula (a′) allow the attachment ofthe radical A onto the silicon-containing chains; and provided that atleast one of L₁, L₂, L₃, and L₄ is chosen from said divalent groups offormula (a) and divalent groups of formula (a′).
 52. A method accordingto claim 51, wherein the keratinous material is chosen from skin, hair,eyelashes, eyebrows, and nails.
 53. A method for treating oxidativestress and/or treating the effects of exposure to ionizing or solarradiation, and/or treating the effects of use of free radical generatingmedicaments, and/or preventing ageing of a keratinous material,comprising: applying to a keratinous material an effective amount of apharmaceutical composition comprising at least one silicon-containingcompound derived from ascorbic acid having at least one group chosenfrom: a) silicone-containing chains having at least one group of formula(1):

b) silanes of formula (2): A—SiR′₁R′₂R′₃  (2) wherein: R is chosen froma trimethylsilyloxy group of formula —O—SiMe₃, and linear, cyclic andbranched, saturated and unsaturated, (C₁-C₃₀) alkyl groups, wherein the(C₁-C₃₀) alkyl groups are optionally partially halogenated or optionallycompletely halogenated; a is equal to 1 or 2, R′₁, R′₂, and R′₃, whichare identical or different, are each chosen from linear and branched(C₁-C₈) alkyl groups, linear and branched (C₁-C₈) alkenyl groups, andtrimethylsilyloxy groups of formula —O—SiMe₃; A is chosen from groups offormula (I):

 wherein: L₁, L₂, L₃, and L₄, which are identical or different, are eachchosen from hydrogen, divalent groups of formula (a), and divalentgroups of formula (a′):

 wherein: groups V, which are identical or different, are each chosenfrom linear and branched, saturated and unsaturated, divalent (C₁-C₆)alkyl groups, wherein said divalent (C₁-C₆) alkyl groups are optionallysubstituted with at least one group chosen from linear and branched,saturated and unsaturated (C₂-C₈) alkoxy groups and hydroxyl groups;groups R₁, which are identical or different, are each chosen fromhydrogen, hydroxyl groups, and linear and branched, saturated andunsaturated (C₁-C₈) alkyl groups; and p, which are identical ordifferent, are each chosen from 0 and 1; q is 0 or 1, with the provisothat p+q is different from 0; wherein said divalent groups of formula(a) and divalent groups of formula (a′) allow the attachment of theradical A onto the silicon-containing chains; and provided that at leastone of L₁, L₂, L₃, and L₄ is chosen from said divalent groups of formula(a) and divalent groups of formula (a′).
 54. A method according to claim53, wherein the keratinous material is chosen from skin, hair,eyelashes, eyebrows, and nails.